The present invention refers to a ballast planing machine of the type having a machine frame supported by undercarriages for mobility along a track, with the machine frame supporting a vertically adjustable ballast plow arrangement, a vertically adjustable and rotatable sweeping broom, a suction unit including a vacuum or negative pressure generator as well as an operator's cabin.
European patent No. EP 0 418 428 A1 discloses a ballast planing machine of this type for shaping the ballast bed of a track, with the sweeping broom being arranged in a suction box which is in communication with a vacuum generator. During operation, dust swept up by the sweeping broom is immediately removed by suction before adversely affecting the environment.
German patent No. DE 21 36 306 A describes a mobile machine for excavating ballast from tracks, with a vehicle supporting a rotatable and swingable boom which carries a suction pipe. The suction pipe enters with one end a ballast storage container and extends beyond the operator's cabin to reach the ballast bed with its other end which is provided in form of a nozzle and acted upon by vibrators for loosening ballast being removed by suction.
Further suction pipes projecting beyond one end of the vehicle for withdrawing ballast are referred to in German patent no DE 91 11 238 U1, DE 90 00 529 U1 and European patent No. EP 0485 810 A1.
U.S. Pat. No. 5,052,132 discloses a ballast distributing and planing machine, with a machine frame including two hingedly connected carrier frames, with the leading carrier frame supporting the vertically adjustable ballast plow arrangement and a ballast storage container, and with the trailing carrier frame supporting the sweeping broom.